Layout¶

Widget description¶
This is a container widget that takes a standard Edje design file and wraps it very thinly in a widget.
An Edje design (theme) file has a very wide range of possibilities to describe the behavior of elements added to the Layout. Check out the Edje documentation and the EDC reference to get more information about what can be done with Edje.
Just like List
,
Box
, and other container
widgets, any object added to the Layout will become its child, meaning
that it will be deleted if the Layout is deleted, move if the Layout is
moved, and so on.
The Layout widget can contain as many Contents, Boxes or Tables as described in its theme file. For instance, objects can be added to different Tables by specifying the respective Table part names. The same is valid for Content and Box.
The objects added as child of the Layout will behave as described in the part description where they were added. There are 3 possible types of parts where a child can be added:
- Content (SWALLOW part)
Only one object can be added to the
SWALLOW
part (but you still can have manySWALLOW
parts and one object on each of them). Use theObject.content_set/get/unset
functions to set, retrieve and unset objects as content of the SWALLOW. After being set to this part, the object size, position, visibility, clipping and other description properties will be totally controlled by the description of the given part (inside the Edje theme file).One can use
size_hint_
functions on the child to have some kind of control over its behavior, but the resulting behavior will still depend heavily on theSWALLOW
part description.The Edje theme also can change the part description, based on signals or scripts running inside the theme. This change can also be animated. All of this will affect the child object set as content accordingly. The object size will be changed if the part size is changed, it will animate move if the part is moving, and so on.
- Box (BOX part)
An Edje
BOX
part is very similar to the ElementaryBox
widget. It allows one to add objects to the box and have them distributed along its area, accordingly to the specifiedlayout
property (now bylayout
we mean the chosen layouting design of the Box, not the Layout widget itself).A similar effect for having a box with its position, size and other things controlled by the Layout theme would be to create an Elementary
Box
widget and add it as a Content in theSWALLOW
part.The main difference of using the Layout Box is that its behavior, the box properties like layouting format, padding, align, etc. will be all controlled by the theme. This means, for example, that a signal could be sent to the Layout theme (with
signal_emit()
) and the theme handled the signal by changing the box padding, or align, or both. Using the ElementaryBox
widget is not necessarily harder or easier, it just depends on the circumstances and requirements.The Layout Box can be used through the
box_
set of functions.- Table (TABLE part)
Just like the Box, the Layout Table is very similar to the Elementary
Table
widget. It allows one to add objects to the Table specifying the row and column where the object should be added, and any column or row span if necessary.Again, we could have this design by adding a
Table
widget to theSWALLOW
part usingpart_content_set()
. The same difference happens here when choosing to use the Layout Table (aTABLE
part) instead of theTable
plusSWALLOW
part. It’s just a matter of convenience.The Layout Table can be used through the
table_
set of functions.
Another interesting thing about the Layout widget is that it offers some
predefined themes that come with the default Elementary theme. These themes can
be set by theme
, and provide
some basic functionality depending on the theme used.
Most of them already send some signals, some already provide a toolbar or back and next buttons.
Layout Class¶
Elementary, besides having the Layout
widget, exposes its foundation – the Elementary Layout Class – in
order to create other widgets which are, basically, a certain layout
with some more logic on top.
The idea is to make the creation of that widgets as easy as possible,
factorizing code on this common base. For example, a button is a layout
(that looks like push button) that happens to react on clicks and keyboard
events in a special manner, calling its user back on those events. That’s no
surprise, then, that the Button
implementation relies on LayoutClass, if you go to check it.
Container parts, here, map directly to Edje parts from the layout’s Edje group. Besides that, there’s a whole infrastructure around Edje files:
interfacing by signals,
setting/retrieving text part values,
dealing with table and box parts directly,
etc.
Finally, layout objects will do part aliasing for you, if you set it up properly. For that, take a look at Elm_Layout_Part_Alias_Description, where it’s explained in detail.
Available styles¶
These are available predefined theme layouts. All of them have class = layout, group = application, and style = one of the following options:
toolbar-content
- application with toolbar and main content areatoolbar-content-back
- application with toolbar and main content area with a back button and title areatoolbar-content-back-next
- application with toolbar and main content area with a back and next buttons and title areacontent-back
- application with a main content area with a back button and title areacontent-back-next
- application with a main content area with a back and next buttons and title areatoolbar-vbox
- application with toolbar and main content area as a vertical boxtoolbar-table
- application with toolbar and main content area as a table
Emitted signals¶
theme,changed
- The theme was changed.